If you're really worried about damaging the sensor, you could always do what I did. I have an old D50 that I use as my high risk body, I used it to practice on. I purchased a cleaning kit complete with a dozen swabs and then cleaned the sensor weekly until I felt confident enough to clean my D700 and D300s. I don't think I spent more than a month cleaning the D50 before moving on, now I feel comfortable cleaning all my bodies. Now that I can clean my own bodies for less than $10 in supplies I tend to clean as soon as I see a spot on the sensor that will not blow off with my rocket blower. I've always wondered what the risk to cleaning infrequently, and putting up with a couple of spots until there was a big enough mess to warrant cleaning. I think that having something stuck to the sensor for a prolonged period of time might give it the opportunity to weld itself to the sensor. Now that I carry cleaning gear with me, I worry less about changing lenses and more about the best setup for the shot. I should also mention that a lit sensor loupe or magnifying lamp (I have one for fly-tying) is a great help.
Will shoot for fame...fun...food... a heck I'll shoot anytime anywhere.